The fifth season of Pwn2Own—the now annual device and software hacking contest—has come and gone. As expected, we have some quickly exploited platforms and some unexpected winners. Among the winners, both Android and Windows Phone 7 have proven themselves impregnable by the hacking teams; but as much as this is a win for Android and WP7, it’s important to know that it’s not conclusive proof that they’re actually safer than their competitors.

According to a Wired article via CNN, in this year’s five-day hackathon pitted a number of handsets against each other and the results are good,

"The survival of a target at Pwn2Own does not automatically declare it safer than a target that went down," last year’s Internet Explorer Pwn2Own winner Peter Vreugdenhil cautions. The contestants who were lined up to beat the Android and WP7 devices in the competition withdrew for a variety of reasons.

Pwn2Own, now in its fifth year, is a hacking competition divided into two areas: web browsers and mobile phones.

As the browser is at the core of the iPhone 4 and Blackberry is Webkit (used by Safari) and that went down in a matter of hours in the browser contest it looks like both are susceptible to very similar exploits. However, Chrome and Android also both use Webkit, so they must be hardened against the species of attacks that managed to get through RIM’s and Apple’s devices’ defenses.

Aftermath has given us some time to interview the organizers and get some idea of why they thing the undefeated remain undefeated.

"Chrome has the advantages of having multiple exploit-mitigation techniques that certainly make it more difficult to hack. As for Android, we see no particular reason why Android would be harder to hack than one of the other targets," explained Peter Vreugdenhil, also quoted above.

Speculation currently is that Apple and RIM devices, such as iPhone 4 and Blackberry, are massive targets of opportunity due to their popularity in the market. A lot of research has been done by both security firms and malware hackers in order to take them down—although, that doesn’t readily explain the unexpected hardiness of Android, which is also extremely popular.